In recent years, ID information is becoming more important. Experimentation on incorporating integrated circuits including ID information has been attempted. Such kinds of applications are expected to continue in the future (see, for example, Japanese Laid-Open Publication No. 2002-83482). Conventionally, a method for physically searching a portable-type optical disc which includes an IC including ID information has not been proposed.
Portable-type optical discs are dispersed after recording of the contents due to their portability. Thus, there is a demand for a method of searching for contents which have been recorded in the portable optical discs. The objective of the present invention is to provide an optical disc and a remote control device which enable searching for contents recorded on an optical disc by mounting an IC including ID information on an optical disc.
The objective of the present invention is also to provide a multi-layer disc capable of switching a target layer without applying a voltage to a conducing layer of a disc directly from outside the disc.
The objective of the present invention is also to provide an apparatus capable of controlling tracking of a laser light irradiated onto a target layer even in the case where no track is provided on the target layer.